ISTANBUL-I love a good ruin. And so, it seems, do a lot of other people if the growing number of archeological tours being advertised in newspapers and magazines is any indicator. I have been particularly drawn to the classical world and have searched out its monument's in the course of my travels. One day, however, I realized that I was visiting only the wonderful cliches of history--the Parthenon, the Coliseum, the Roman Forum--and not the less trammeled but equally exciting remains of Greek and Roman imperial greatness that lie tumbled all around the edges of the Aegean and Mediterranean seas. Turkey alone has more Greek ruins than Greece and more Roman cities than Italy. Trouble was, I could never figure out a way to get to such sites on my own.

Then came the opportunity to go on a bus tour of Turkey led by an archeologist/architectural historian. His itinerary--which offered more than a dozen centers of ancient Greek and Roman culture--might have been lure enough, but the price last year was irresistible: $900 per person (without air fare) for 14 days, including hotels, most dinners and breakfasts and a Turkish guide.

Prof. Robert Lindley Vann of the University of Maryland would prove an amiable and knowledgeable leader, bringing to our group his skills as a teacher and a popular lecturer on classical architecture at the Smithsonian Institution. Gray- haired, trim and relaxed, he is the kind of telegenic communicator who would make a fine host on an educational TV show.

The professor had little trouble persuading us that in Turkey, the old Anatolia of the history books, the past is everywhere. Not only, of course, was this East Greece between 750 and 130 BC, but also a province of the Roman Empire between 130 BC and AD 395. Here strode Aristotle and Alexander the Great; the Roman emperors Trajan, Hadrian and Constantine; St. John the Evangelist and the Virgin Mary, and a host of other awesome figures.

In fact, on our first day in Turkey, we found that the past lay just a stone's throw from our Istanbul hotel, the Ferhat, in the venerable Sultanahmet district. Down the street was the site of the hippodrome, the Roman racecourse, now a park, where a 3,500-year-old obelisk removed from Egypt by the Byzantine emperor Theodosius still stands, close by the remnant of the bronze monument erected by the Greeks at Delphi in 478 BC to commemorate their victory over the Persians. And farther on lay the cistern, an enormous underground reservoir constructed between AD 527 and 565. Its high ceiling is held up by a forest of 336 giant, often mismatched, columns removed from Roman temples and monuments. It is an eerie space of dripping water, long slippery walkways and deep shadows that puts in mind the moody etchings of the 18th-Century master engraver Giovanni Battista Piranesi.

However much my wife, Liet, and I wanted to linger in this city that

straddles both the European and Asian continents, we were eager for our tour to begin. The names of some of the places we would be visiting--Chryse, Assos, Erythrae, Clarus, Priene, Miletus--called out like Odysseus' Sirens. And so, on the third day. we enthusiastically boarded our bus, in the company of 20 congenial adults and architecture students. One of the advantages of such a specialized tour, we would soon find out, is a commonality of interest that guarantees that everyone will stop and listen as the leader holds forth and that conversations afterward will be spirited.

Our first stop was Troy, scene of Homer's "Iliad." Now an oversize wooden Trojan horse guards the gate, a hokey modern tourist attraction that can be entered via a steep flight of steps. But it is Homer's ghost that really hovers over the place, imbuing its stones and dust (and it is dusty ) with special meaning.

There were, all told, nine Troys, each new city built over the ruins of the other in an ever-growing mound through which archeologists have cut to reveal walls of houses, palaces and defenses. The top layer is Roman and the bottom dates all the way back to 3000 BC. In his zeal to find the Troy of the "Iliad," the renowned German archeologist Heinrich Schliemann, who began his excavations here in the 1870s, dug right past the level he was looking for, mistaking a burned layer underneath for the city of Homer's description. The scene of Schliemann's labors survives today, a broad, deep gulch, where red poppies were blooming among the stone foundations of houses when we lingered there.

Soon we were to discover the second advantage of a specialized tour, the opportunity it presents to get off the beaten track. This was true of our second site, the small town of Chryse. There, the ruins of the Greek Sanctuary of Apollo Smintheus, the Mouse God, lay in weedy disarray, tucked behind sleepy whitewashed houses and pomegranate trees in full, fiery orange bloom. Our challenge was to divorce the temple from its 20th-Century context and in our minds re-erect its fallen columns to envision it In all it's s former glory.

A romantic imagination. I could see, is a prerequisite of archeological touring. And mine was beginning to be fired up with thoughts of the ancients who had called this sun-struck land home. Wherever our Turkish driver Haluk took us, we found Kodachrome-blue skies, silvery olive trees and ripe wheat. To me it was a wonder that these hills and valleys, farmed almost since agriculture began, are still productive.

With my imaginative juices now flowing, I was primed for our third site, Assos, where ruins of a Greek city dating from the 7th Century BC lie atop a mountain. "Spoiled" said one guidebook of the surroundings, but perhaps because we were traveling in June, in advance of tourist hordes, we found the place practically deserted and very charming. We were let out of the bus halfway down the steep slope, so that we might walk to Assos' ancient harbor, where the stone buildings of a little fishing village have been converted into accommodations for foreign visitors. It was noon, the sun was hot and our thirst sticky--but we were quickly diverted by the sight of the large Greek island of Lesbos rising from the azure Aegean off to the left and of pink hollyhocks, which grow wild in Turkey, thrusting up on either side of the narrow road.

At the water's turquoise edge, our group was invited by members of the hotel staff to seat ourselves at a row of tables lined up on the stone wharf. There, protected from the sun by a slatted canopy of bamboo, we were brought bottles of mineral water, wine, and delicious mixed appetizers and grilled fish. Not the least pleasant aspect of our three-course lunch was its price The bill came to barely $7 a head. In Turkey, the beleaguered dollar has value.

After a nap, our group reassembled and we hiked back up to the bus, which took us to the modern village situated below the site of the ancient city. A scramble to the top brought us to the Temple of Athena ( 6th Century BC ), its surviving Doric columns starkly silhouetted against miles I and miles of sea and sky. The Greeks, said

Vann admiringly, loved a good view.

After wandering in and around the temple, we followed our leader down through brush and thistles to the remnants of the city's imposing, 1th Century BC defensive wall. The most complete surviving fortification of the (Greek world, it once ran three miles .round the settlement. Where the slope broadened into a kind of platform, enormous sarcophagi yawned open, their lids topsy turvy or overturned. The road they lined lay partially excavated below us, some six feet down in the earth, an eerie reminder that I was standing on accumulated layers of time and that one day our own thin layer would be covered over by the future.

The street led straight to the city's gate, through which we passed to reach the agora, the public assembly spot where Aristotle--who lived in Assos for three years--had walked. Today, this once-grand space is little more than a rumpled field, with stray bits of rubble poking up here and there. But it :s pure in that apparently nothing was built over it after Assos' decline. Where Aristotle's footsteps fell, so now did mine.

Our next big site, on the fourth day of our journey, was Pergamum, the city that invented parchment, or pergamena in Latin, and hence the book. In its Hellenistic heyday it had had more than 100,000 inhabitants. We spent a morning poking around its lower portion. the Asclepion, the medical center named for the god who was so skilled at healing he could revive the dead. The ill came to this spa from all over the ancient world.

Treatments included mud baths, massages, herbal medicines, colonic irrigations, drinks from the sacred spring, and abstinence from wine and rich food. But a bit of hocus-pocus seems to have been part of the regimen, too, with clients obliged to run around barefoot in cold weather and to sleep in snake-filled rooms. For those with mental problems (and who wouldn't develop them with snakes slithering about? ), dream interpreters were at hand to administer an early form of psychotherapy.

And to entertain the patients, actors performed regularly at a little theater still in use today. When we wandered into its marble embrace. we discovered that sound gear and electric cords incongruously filled part of the stage and, that numbers had been chalked on the seats for the convenience of ticket-holders who the night before had attended an international festival featuring a Polish choir.

Pergamum's acropolis floats high above broad valleys and must have rivaled Athens' in the beauty of its columned marble building. The ruin-rich summit offers splendid vistas, but none so moving I thought as the view that opens up directly in front of the platform on WhiCh the Altar ef Zeus, one of the masterpieces of the hellenistic period, used to stand. (The greater part of this building-size monument now resides in Berlin's Pergamon Museum.

Germans are excavating at Pergamum today, and they have done much to restore the 'Trajaneum, a Corinthian temple completed by the great Hadrian in honor of his mentor and patron Trajan. Its gleaming sugar-white marble can bleach color from the eye, if stared at too long.

Thanks to such reminders of a long vanished time. the ancients themselves seemed to draw us with each passing day. At Clarus, I felt them particularly near at hand. This was once a much-revered, much-famed cult center, known throughout the Mediterranean region for its oracle, who delivered her prophesies in a dark room 1 under the Temple of Apollo. Above ground, neat rows of names of the countless ancient visitors are carved on columns, steps and even on a curving marble bench. I sat in an elegant marble chair with serpent arms, spotting a snake slithering into the reeds as I did so--and spent a few moments reflecting on the past. What, I wondered, had the people who flocked to this temple from all over learned about themselves and their futures after paying the price of admission and listening to the cryptic messages of the oracle? Did they go away happy, or wary? I was jostled back to reality by the odor of 20th- Century resins floating on the air; a group of French archeologists were busy making molds of parts of colossal statues--an arm and a torso, among them--that remain at the site.

Soon we were off to our next destination, the Temple of Artemis, a powerful earth goddess and friend to women in a male-dominated society. Once one of the Seven Wonders of the Ancient World the temple ranked as the largest edifice of the Hellenistic period, and the first monumental' structure ever to have been built entirely; of marble. Now, sad to say, it's no more than a hole in the ground, with only a single column standing. But we had not come to the town of Selcuk to see this alone; rather, it was to visit nearby Ephesus, the great Roman city where tradition says St. John the Evangelist brought Mary to live after the crucifixion of Jesus.

Ephesus was grand, with its baths, temples, theater and library, the last almost a logo) today for Turkish tourism, so often does it appears in ads and booklets. The familiar structure--actually nothing more than a reconstructed facade--rises three stories tall. To stand beneath its porches and look up past the tapering columns and all the rich carvings to the coffered ceilings is suddenly to understand that Rome conquered the Mediterranean not just with its might but with its architecture.

BY now an easy camaraderie had grown among the tour's participants, and after visiting Ephesus and Pergamum, we could kid Vann about some of the all-but invisible sites he was taking us to. These consisted of ruins so scant I might easily have passed by them without knowing what. they were. Two such places were the lost cities of Larissa and Erythrae. today marked only by a few stray walls, chipped blocks of stone and broken bits of pottery. Yet the climb to them, the wide-angle views they offered, and the exhilaration of being out in the Turkish countryside, to say nothing of the exquisite sic-transit- gloria-mundi melancholy they project, made the expenditure of energy worthwhile.

These near-invisible sites stood in vivid contrast to Miletus, where a gigantic

Greek-Roman theater dominates the terrain. and Didymi, whose Temple of Apollo (famous, like the one at Clarus, for its oracle) is so huge its remnants put Egypt's monuments in mind. To get inside the theater We had to pass through a vomitory--not what it might sound like, but an arched entrance---then climb stairs before coming out' into the open.

Vann loved all these sites, and could wax poetic about them, but his personal favorite was Priene, a Greek city that was never tainted by a roman overlay. He made sure to share it with us at the best time of day for viewing ruins in Turkey, the late afternoon, when a breeze is up, the light is soft and golden, and the shadows are long. Priene's acropolis soared above a broad valley that was once an inlet of the sea; silt from the River Meander had gradually filled the bay, leaving the city high and dry, destroying its commerce--helping to protect the town's Greek character from too many Roman architectural incursions. An enormous stone- faced mountain reared directly behind Priene forming a strong backdrop for several Ionic columns reerected in a solemn row.

Instead of the gentle breeze we expected, we encountered a wind strong enough to shake one of the columns, yank off my cap and drop it on someone else's head like a gift from the gods, and spread the warm perfume of pine tree needles over the ruins. In this aromatic environment we wandered around by ourselves, practically the only visitors, and the unadorned strength--the Greek severity--of the place took hold of us. The streets were laid out on a strict grid plan. and the facades of many of the houses faced south, so that the sitting rooms at the front would receive the warmth of the sun during winter.

The greatest archeological site of all Vann had saved for last: Aphrodisias. named for the goddess of love. Excavations began in the 1960s when an earthquake destroyed the Turkish village that had grown up over the ruins. As a center of Roman marble-carving and sculpture, Aphrodisias had flourished, sending its statues and artists all over the empire. The archeologists' spades did not have to plunge deep before statues began appearing. Nor were these their only finds. More and more of the city came to light, including much of the Temple of Aphrodite, which, during its post-Roman history, had been converted into a church.

We were lucky to have the director of excavations, Chris Ratte of New York University, give us a quick, behind-the- scenes tour of Aphrodisias. We entered through the Tetrapylon. a gateway of beautifully twisted columns, that led to the sprawling temple, then hopped, quite literally, from excavation to excavation to see the odeon, or concert hall!, and the senate house. Next we galloped along one of the city's two long agoras to the so- called depot, where statuary recently retrieved from the earth is stored.

Among Aphrodisias' many thrilling sights are the stadium and the theater The stadium--which is 860 feet long and held 30,000 spectators--is not only the largest to have survived from ancient times, but also one of the best preserved. Once used for footraces, it challenged two of the younger members of our group to run its length under the hot sun. And since my imagination was by now working over time. I populated the seats with the ghosts of all those cheering individuals who had sat on them centuries ago. little did I know that in moments, I would meet one of them.

Leaving the stadium behind, we strolled into the 7,000- seat theater and climbed to-its highest level, there to sit in the shade o. a wall and take in the view of the distant mountains. I turned around to look behind me, where at some point part of the wall had given way. I spotted a bone poking up from the earth. l pulled at it and it came away easily. Then I saw a tooth. I picked it out and showed it to Vann on the palm of my hand. Was it human? Yes, he said matter-of-factly. Tooth and bone, he suggested, might well have belonged to, a Roman killed in an early earthquake. Gently I poked both back into their resting places Never did the ancients seem closer--or time more fragile.

*****

Brown, Based in Virginia, is editor of Time-Life Books' archeological adventure series, "Lost Civilizations."